Nigerian health authorities are on full alert to watch out for possible cases of swine flu in Africa's most populous nation. The government has set up a committee to monitor the situation and co-ordinate with the World Health Organization.

No case of swine flu has been reported in Nigeria, but the country has joined the race to contain the deadly outbreak of the influenza virus. 

Health Minister Babatunde Osotimehin says Nigeria is focused on early detection and response in an attempt to check a possible outbreak in the country.

"As we speak, there is no known case of swine flu in Nigeria," said Osotimehin.  "But we are not going to wait for it to occur before we take adequate steps.  We have constituted a committee that is putting surveillance in place to detect cases if they occur."

The virus is blamed for more than 150 deaths in Mexico.  In at least 10 other countries, there have been confirmed or suspected cases, none of them fatal.  Several countries are investigating suspected cases. 

The World Health Organization called for all nations to "intensify surveillance."  The health minister says Nigeria has placed its ports on high alert.

"An alert has gone out to our colleagues at the airports and seaports to look out for this because they will have to come from abroad, since we do not have any case in this country at this point in time," said Osotimehin.

Swine flu is caused by a virus similar to a flu virus that infects people every year, but it is a strain typically found only in pigs, or in people who have direct contact with pigs.

Serious concerns have been expressed about Africa's capacity to deal with a pandemic, given the poor state of health infrastructure in sub-Saharan Africa.  Nigeria is still grappling with a bird-flu outbreak, years after it was first detected.